The purpose of this investigation was to develop a measurement system used for the characterization of linear and nonlinear dielectric properties of organic monolayer films, and to measure Maxwell-displacement current (MDC) and Second Harmonics Generation (SHG) from monolayers on a water surface. Further to analyze monolayers based on a hardcore monolayer model was the purpose. Thus, this investigation has been carried out on the basis of the idea of Maxwell-displacement current measurement proposed by the investigators. The investigators analyzed the molecular motion of organic monolayer films using a rod-like polar molecular model, assuming the motion of molecules is ruled by the Boltzmann statistics. They theoretically derived dielectric relaxation time of monolayers and also analyzed the generation of MDC from chiral and achiral monolayers. They also analyzed the phase transition of monolayers and explained the chiral phase separation of mixed monolayers using a continuum theory. The relationship between the orientational order parameters, i.e., 1st 2nd and 3rd orientational order parameters, and the MDC and SHG signals were obtained. They also measured the MDC and SHG from 5CB liquid crystal monolayers. Further orientational transition process of LCs triggered by conformational change of azobenzene and the molecular motion of azobenzenes in mixed monolayer systems were analyzed based on a continuum theory, and the motion of LCs was discussed based on the simultaneous measurement of optical transmittance and the capacitanace.